This invention relates to a stepless speed change device capable of changing its transmission speed in a stepless manner by frictionally engaging wedge-shaped friction pieces with V-shaped grooves and particularly suitable for a bicycle.
Such a stepless speed change device has been known as disclosed in Japanese Patent Application Laid-open No. 61-218,491 filed by applicant of this case. However, this stepless speed change device of the prior art is so constructed as to be applied to a rear wheel hub of a bicycle. Accordingly, it could not be applied onto a crankshaft of a bicycle.